Apparatus for cutting coal pillars



April 23, 19356 J. R. LAWSON APPARATUS FOR CUTTING COAL PILLARS Filed Feb. 20, 1934 2 Sheets-Sheet 1 A ril 23 1935. J. R. LAWSON APPARATUS FOR CUTTING COAL PILLAR S Filed Feb. 20, 1954 2 Sheets-Sheet 2 Patented Apr. 23, 1935 UNITED'STATES eArENr OFFICE John R. Lawson, Denver, 0010.

Application February .20, 1934, Serial No. 712,227

4 Claims.

This invention relates to improvements in apparatus for mining coal.

The primary object of the present invention is to provide improved apparatus for progressively cutting through a pillar of coal where there is an open space around the same whereby operating cables can be passed thereabout.

Another object of the invention is to provide an apparatus for cutting horizontally through a coal pillar and for constantly maintaining the correct contact pressure between the cutting elements and the coal surface as the cutting elements are moved constantly thereacross.

Still another object of the invention is to provide apparatus for cutting through a pillar of coal, wherein means is employed for constantly moving a gang of reciprocating cutters forwardly against the face of the kerf which they form.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings Figure 1 shows, in plan, the mechanism embodying the present invention and operating upon a coal pillar which is in horizontal section;

Figure 2 is a vertical side elevation of the pillar and the part of the mechanism upon the adjacent side thereof;

Figure 3 is a sectional View taken substantially upon the line 3-4 of Figure 2; v

Figure 4 is a sectional View taken substantially upon the line l-t of Figure 2;

Figure 5 is a sectional view taken substantially upon the line 55 of Figure l;

Figure 6 shows inside elevation a modification of a part of the structure.

Referring now more particularly to the drawings wherein like numerals of reference indicate corresponding parts throughout the several views, the numeral 5 indicates a representation of a pillar of coal which is to be horizontally divided. In mining operations these pillars are formed by the construction of corridors or cuts such as that indicated by the numeral 2 and it is then necessary to cut out the dividing columns of coal and the preferred method of doing this is by drawing acrossthe same a gang of cutters such as those indicated by the numerals 3, these cutters being flexibly coupled together and having connected with each end of the gang a cable l. The cutters 3 are disclosed in detail and form the subjectmatter of Patent No. 1,892,344, of January 3, 1933.

In carrying out the present invention there is set up adjacent each of two corners of the coal pillar i, a column or post 5 between which is p0- sitioned a suitable engine structure 6 which includes a pair of cable drums each of which is indi-- cated by the numeral l and which are suitably coupled with the engine 6 so that they may be alternately driven first in one direction and then in the other so that the cables 4 which are wound thereon may be alternately payed out and taken up.

Each of the posts 5 has secured thereto a bracket 8 in which is mounted a sheave 9 over which a cable 6 passes. 7

Upon each side of the pillar I there are located the two posts it, each of which is preferably made extensible by having the head ll threaded into the upper end thereof so that it may be tightly secured in position between the ceiling and floor or the cut or corridor in which it is mounted. V

The two posts It upon each side of thecolumn are disposed in spaced relation and the one near: est that end of the pillar farthest removed from the sheaves iiis closer to the pillar than the adjacent post so that the two beams 12 which are mounted in spaced parallel relation between each pair of posts are obliquely disposed relative to the adjacent side face of the pillar. These beams '12 are of the type having channeled side faces as clearly shown in Figure 4 and adjacent each post a plate [3 is disposed across the beams and has connected therewith the free ends of a U- bolt I l which encircles the adjacent post and draws the beams securely thereagainst.

Disposed between each pair of beams i2 and extending therefrom toward the adjacent pillar, is one end of an arm l5 which has its other end bifurcated as indicated at it and supporting the sheave H in the bifurcation. The end of the plate {5 which is between the beams i2 carries the two rollers l8 which are mounted on vertical pivots carried by the plate and position in adjacent beam channels.

Each of the sheaves I! has a cable 4 passing thereabout as shown in Figure I so that the cable leads inwardly from these sheaves substantially at right angles to the side faces of the pillar.

The lowermost one of each pair of beams I 2 has mounted upon the end remote from the engine 6, the sheave i8 and secured to the lower end of the adjacent post it is a bracket [9 upon which is carried a sheave Each of the posts 5 has secured thereto a bracket 2i which carries a sheave 22 and mounted upon a suitable shaft such as that indicated by the numeral 23, adjacent the engine 6, is a drum 24 about which are wound the ends of cables 25 which have their other ends trained over the sheaves 22, 25 and I8 and connected with eyes carried by the arms 15 upon the sides thereof nearest the sheaves E8.

The cables Eli are wound in the same direction upon the drum 26 but approach the same from opposite sides so that one passes over the top and the other under the bottom as shown in Figure 5.

In the operation of the mechanism the cables 25 are constantly subjected to a pull from the ends connected with the arms [5 and it is, therefore, necessary that some suitable means be employed for preventing the drum turning so that the cables will constantly unwind therefrom and while any suitable means may be employed, there has been illustrated a drum 25 mounted upon the end of the cable drum 24 concentric with the shaft 23 and about this drum a friction or brake band 23 passes which is connected with a suitable pivotally mounted lever 29 which may be secured in any one of several adjusted positions, in one of which the band is drawn tightly against the drum 2? so as to hold the cable drum against rotation while in the other it is loosened so that the cable drum may rotate freely.

In Figure 6 there is illustrated a modified construction for controlling the cables which are connected with the sheave carrying arms l5. In this construction the cables 25 which pass over the sheaves 18, are wound directly upon drums or Winches 36 which are mounted upon a suitable bracket 3| secured to the adjacent post [0. These winches are provided with a crank 32 and a pawl and ratchet 33 by which they are normally held against rotation.

In the operation of the mechanism, referring now to the structure disclosed in Figure 1, the cables 4 are alternately wound up on andpayed out from their respective drums I. That is, the cable 4 upon one side of the pillar is being payed out while the cable 4 upon the opposite side is being wound up so that the gang of cutters 3 is constantly drawn back and forth across the end of the pillar of coal remote from that end adjacent which the engine 6 is located. The sheaves H are mounted for movement toward the end of the pillar adjacent which the engine is located so that the cutters may be constantly moved along as the cut ismade, the cables connected with the cutters being taken up as necessary upon their respective drums. The mechanism comprising the cables 25 and parts with which they are connected is provided to prevent too great pressure being applied by the cutters 3 to the coal surface and thereby causing the cut ters to dig in too deeply and thus be stopped in their operation. These cables 25 being connected with the sides of the arms I5 remote from the engine 6, prevent the arms being pulled along too rapidly. As it is necessary for the cutters to move forward the attendant at the engine releases the engagement of the brake band with the brake drum 21' thus permitting the pull upon the cables 4 to draw the arms 5 forwardly and at the same time draw some of the cable 25 off of the drum 24. The structure illustrated in Figure 6 permits of the slacking of the cable 25 from a point adjacent the end of the channel beam l2 upon which the sheave I8 is'mounted. In this construction an attendant stands at each of the corners of the pillar remote from the engine and releases the pawl of the pawl and ratchet mechanism 33 and permits the cable 25 to be drawn off of the drum 3&3 so that the cutter gang may move forwardly as the kerf is formed in the coal body.

From the foregoing it will be readily apparent that with the mechanism herein described the cutting operation of the coal pillar may be carried forward without interruption and at the same time the correct amount of contact pressure between the coal and the cutter units may be maintained to obtain the greatest amount of cutting action.

Having thus described the invention, what is claimed is:

1. Mechanism for cutting a pillar of material transversely, comprising a cutter, a pair of cables connected with opposite sides of the cutter, mechanism connected with said cables adjacent the face of the pillar opposite that engaged by the cutter for eifecting the reciprocation of the cables and cutter and the taking up of the cables to move the cutter forward, a guide track disposed adjacent each of the sides of the pillar which adjoins the face engaged by the cutter, a pair of sheaves each being slidably mounted upon a guide track, and having a cable passing thereover, a cable drum, a pair of cables connected with the drum and each having one end connected with a sheave upon the side of the sheave facing away from the direction in which the sheave is moved, and means for controlling the rotation of said drum.

2. Mechanism for cutting a pillar of material transversely, comprising a cutter, a pair of cables connected with opposite sides of the cutter, mechanism connected with said cables for reciprocating the same and the cutter and for advancing the cutter in the direction of cut, the cables encircling the pillar, a pair of guides, each guide being disposed adjacent one side of the pillar in proximity to the face engaged by the cutter, a pair of sheaves each being slidably mountedupon a guide, each of said sheaves having a cable passing thereover, and moving on its guide in the direction of movement of the cutter through the pillar, a rotatably mounted cable drum for each of said sheaves, means for controlling the rotation of the drums, and a cable wound upon each of said drums and having an end connected with the adjacent sheave upon the retreating side thereof and permitting the sheave to move on its tracks only when the drum is free to rotate.

3. Mechanism for cutting a pillar of coal transversely, comprising a horizontally disposed guide track disposed adjacent each of two opposite sides of the pillar, a bracket mounted for movement along each guide track, a sheave carried by each of said brackets, said guide track extending at one end from a point adjacent the plane of a right angularly disposed side wall, a cutter element adapted to be drawn across the last mentioned side wall of the pillar, a pair of cables connected with opposite sides of the cutter element and each passing over one of said sheaves and extending to a point adjacent the center of the other right angularly disposed pillar wall, mechanism coupled with said cables for eifecting reciprocation of the cutter therethrough, a pulley element mounted adjacent the end of each guide track nearest the cutting element, a pair of cables each connected at one end with a sheave bracket and passing over the adjacent pulley elements, and a drum having the last mentioned cables wound thereon and operable for the controlled unwinding of the same therefrom.

4. Mechanism for cutting a pillar of coal transversely, comprising a horizontally disposed guide track disposed adjacent each of two opposite sides of the pillar, a bracket mounted for movement along each of said tracks, a sheave carried by each of said brackets, said tracks extending at one end from a point adjacent the plane of a right angularly disposed side wall, a cutter element adapted to be drawn across the last mentioned side wall of the pillar, a pair of cables connected with opposite sides of the cutters and each passing over one of said sheaves and extending to a point adjacent the center of the other right angularly disposed pillar wall, mechanism coupled with said cables for effecting reciprocation of the cutter therethrough and at the same time advancing the cutter towards the pillar, a pulley element mounted adjacent the end of each track nearest the starting position of the cutter, a cable drum mounted adjacent each pulley element, a cable wound upon each drum and passing over the adjacent pulley element to and connected with the retreating side of the sheave bracket, and means for controlling the rotation of said drums.

JOHN R. LAWSON. 

